Evacuator



K. KIEFER April 7, 1931.

EXCAVATOR Original Filed Dec. 18, 1922 Inventor 70 M4 CUUH PUMP case No. 607,757.

- be evacuated therefrom back to the liquid I Patented Apr. 7, 1931 PATENT OFFICE m1. KIEFER, or CINCINNATI, OHIO Continuation of application Serial No.

This case is a continuation of co pending My invention relates to devices for removing liquid from systems closed to the atmosphere, especially from Vacuum systems used "in filling liquids into containers, wherein the overflowis drawn into the system and must supply.

The object of my invention is to simplify and increase the reliability of devices of this character. Other objects will appear in the course of the ensuing description.

I attain these objects by the device illustrated, for example, in the accompanying I drawing, in which- Figure 1 is a plan view of the device in connection with a vacuum-operated filling apparatus; and

Fig. 2 is a vertical section on theplanes of the broken line 2-2 of Fig. 1.

The filling apparatus shown is similar to that disclosed and claimed in my co pending application, Serial No. 544,236, filed March 16', 1922. The-filling head 1 has a filling tube 2 projected into the container-A with a gasket or seal 3around itagainst the container top. The vacuum pipe 4 leads from the top of this head,' and a small overflow tube'5 leads into the vacuum pipe 4 from an opening out through the side of the filling tube 2 just above the lower open end in the container. The supply pipe 6 leads from the lower part of the reservoir 7 up into the side of the filling head 1 to the annular space around the overflow tube therein, whence the liquid is discharged through the filling tube 2 into the container. A check valve 8 prevents backflow from the head to the reservoir. As air is exhausted from the container A through the vacuum pipe- 4, atmospheric pressure on the liquid in the reservoir7 forces the liquid up through the supply pipe 6, past the check valve 8, into the container. When the liquid has risen in the. container to the mouth of the overflow tube 5, further inflow of liquid is drawn out through the vacuum pipe 4 until the container is removed, whereupon the pressure is balanced at the open end.

of the filling tube, by the atmosphere, hold- 607,757, filed December 18, 1922. This application filed January 7, 1928. Serial No. 245,235.

ing the liquid up that remains it the tube;

height. Fig. 2 shows the disposition of the liquid at'this stage of the-operation, filling the container, the filling tube, the supply pipe, the overflow tube, and the vacuum pipe, andfiowing therefrom into the evacuator.

This evacuator comprises the casing 9-, down through the top of which leads the vacuumpipe 4. A continuation 10 of this vacuum pipe 4 leads out through this top, and will be understood to communicate with suitable apparatus for maintaininga desired degree of vacuum inthe pipe 4, casing or chamber 9, and continuation of the vacuum pipe 10. I The bottom ofthe chamber 9 consists .of a centrifugal-pump casing 11 in which the rotor or impeller 12 rotates on a vertical axis, having a shaft 13 projected down through a stuifing box 14 to a suitable motor 15. The inlet to this centrifugal pump is a central opening 16 in the bottom of the chamber 9, and the outlet 17 it as one peripheral side of the pump'casing 11, preferably tangential thereto (Fig. 1) as is common-in centrifugal pumps. This outlet leads, by a pipe 18, down into the reservoir 7 from which the filling apparatus is supplied; extending far tevacuator is. balanced by ,the centrifugal efi'ect of the impeller 12 on the liquid coming down from the chamber. 9; resulting in the liquid .being'disposed in the pump casin 11 out around the peripheral interior thereo as indicated at B, Bin Fig. 2, continuous with the liquid in the outlet pipe 18 and reser-- voir 7.. As more liquid enters the chamber 9 from the vacuumpipe4, it drops to the hottom of the chambers and flows into the pump casing 11, where the impeller 12, acting with greater centrifugal effect on the heavy liquid than on the air of the partial vacuum in the enclosure,.forces this liquid out to the periph- 10 ery, separating it from the air which is to be drawn out through the vpipe 10, and thus thoroughly preventing accumulation of liquid in the vacuum pump and its connections. The liquid thus/thrown out displaces an equal amount of liquid out into the reservoir 7,

against atmospheric pressure.

The centrifugal pump, on'an upright axis with its central inlet opening upward is self priming, because the air is separated, and

rises through the inlet, by the difference of centrifugal efi'ect before noted, instead of accumulating in a peripheral part of the pump, as it can, for example, in the upper part of such a pump operating on a horizong5 tal axis, or throughout the upper annular part of a casing where the pump, although on an upright axis, has its inlet opening downward. The air thus cannot form a pocket as it does in the above instances, ex- 3o eluding liquid from part of the casing eripheral interior and thus delaying full e ective operation of the pump, on starting. This is of advantage in any use of a centrifugal pump; and especially so in its use for evacuation of a vacuum system in my present invention. Upon starting the vacuum ap aratus and this'pump, the impeller 12 quic ly fills the peripheral part of the 'casingwith the first-overflowing liquid, to- 40 meet w1th li u1d forced up from the reservoir 7 throug the outlet pipe 18 as soon as the pressure begins to fall in the vacuum chamber 9.

The separation of the liquid from the air I in the vacuum system, and theremoval of this liquid from the system, is thorough and contlnuous as long as the impeller is rotated while there is overflow from the filling device. In intervals between overflows, the continned rotationkeeps the liquid out away from the main body of air of the partial vacuum being maintamed; and at the beginning of overflow there is immediate separation and outflow of the overflowed liquid as soon as it has dropped into the pump casing. The

device is extremely simple, having but one movinginterior part, the impeller 12; and

its operation is continuous and positive, as

distinguished from intermittent operations,

. usually depending upon difl'erences of pneumatic or hydraulic pressure, in prior evacuators, traps and the like. This advantage is especially realizedwhen the liquid overflow: ing into the system 1s heavy, viscid or sticky,

- as in filling syrups or other sugary liquids with apparatus such as illustrated herein, and

' which causes sticking of valves that must be controlled by the differences in pressure, as

above alluded to. i

The device is illustrated in conjunction with a filling apparatus, but is will be understood that other uses of it may occur; and while a peculiar use and certain constructional details have been described specifically herein, I do not wish to be understood as i chamber, and of constantly running centrifugal means for freeing the overflow from air, and transporting only liquid to the atmospheric supply reservoir.

- KARL KIEFER. 

